Reenforced concrete cribbing



Oct. 16, 1928. 1,688,305

.I. M. FITZGERALD REENFORCED CONCRETE CRIBBING F'iled Oct. 30, 1925 2Sheets-Sheet 1 v zfl ll for. 7521/ 71/ raazi Oct. 16 J. M. FITZGERALDREENFORCED CONCRETE CRIBBING Filed Oct. 50, 1925 2 Sheets-Sheet 2Patented Oct. 16, 1928.

JOHN M. IEI'1ZGERALD, OF RIVER FOREST, ILLINOIS.

BEENEOBCED CONCRETE GBIBIBING.

This invention relates to new and useful improvements in reenforcedconcrete cribbing of pre-formed units, and more particularly toimprovements upon the type of crlbbing illustrated in the patent toRobert H. Ford, et all, No. 1,312,689, dated August 12, 1919, althoughit may be applied to other types of concrete cribbing.

In the patent referred to the spaces between the superposed layers ofstretchers in the cribbi'ng wall are substantially equal to thedimension of the stretcher; that is to say, if the stretcher body is 5"by 5", the space between the bottom surface of the stretcher member andthe top surface "of the next subjacent member will be approximately 4,and this distance is increased when certain other types or forms ofheaders and stretchers are use It is found that the natural angle ofrepose of the filling material is such'that when cribbing of thisgeneral type is used, the earth, especially if of a sandy character,spills through the open-in s and is carried away too freely by water.

invention is to provide spaces in the cribbing wall which shall besufliciently large to per-T mit the passage of the water and yetsubstan-- tially prevent the improper passage of the filling materialtherethrough. p To this end the invention consists in the constructionillustrated and described and more particularly pointed out in theappended claims.

In the drawings:

Figure 1 illustrates in a perspective view, a cribbing composed of unitsembodying the invention, but with the filling material omitted.

Figure 2 is a front elevation of the crib wall 40 showing the stretcherunits in side view and the header units in end view. 1 v

Figure 3 is a view in elevation showing the superposed header unitswithout the stretchers.

Figure 4 is a transverse, sectional View, enlarged, through thesuperposed stretcher units,-the section being taken in the plane of thevertical line a 'a of Figure 2.

Figure 5'is a view similar to Figure 4 but showing a modification inconstruction of the stretcher units.

ne of the objects of this.

Application filed October 30, 1925. SeriafNo. 65,729.

Figure 6 is a transverse, sectional view, enlargZd, of one of thestretchers shown in Figure In the particular form of cribbing unitswhich I have chosen to illustrate the present invention, it will be seenthat the cribbing is composed of a plurality of courses of headers 19and stretchers 13, so disposed that the varlous courses composed ofstretchers and interlocking header ends,.lie in a vertical row or wall,while the headers proper extend, transversely, in another vertical row,thus forming the cellular cribbing. structure.

The headers 10 consist of properly reenforced concrete, of the desiredpredetermined size, both as to length and cross section. As

shown, and preferably, the body of the header is substantiallyrectangular in cross section. Each header is formed at one or both endswith laterally-extending flanges 11, 11,Which give a T-shaped form tothe header end. These flanges are flush at one end with the top surfaceof the header body, but extend below the bottom surface of the,header,this downwardly extending portion 12 constituting an integralspacer member.

The stretchers 13 are also composed of reenforced concrete ofpredetermined length and dimensions. The body of the stretcher is also,

preferably, substantially rectangular in cross section, and the samesize as the body of the header. As shown, the ends of the stretchers 13are provided with kerfs 1 1 which are adapted for interlockingconnection with the flanges constituting the T-shaped end of the header.The stretcher ends are also provided with a spacer member 15 integralwith and extending downwardly below the lower surface of the stretcherbody. The spacer members 15 and'12 are substantially of the samevertical dimension.

Some of the stretchers, it will be observed, are longer than others, andthis permits of laying the courses in what is familiarly known as abreak joint construction, as clearly seen in Figs. 1 and 2. When it isdesirable to break joints, itis found to be convenient to place on thelong stretchers intermediate their ends, a downwardly extending lug orportion 16 of the same height as the stretcher member 15.

Depending from the bottom surface of the stretchers is a curtain 17which, as shown in Figs. 2 and 4, has a front face or wall 8 coin cidentwith the front face f of the stretchers. Said curtain is wider at itstop where it joins the lower face of the stretcher than at its bottomedge 18, and is of less height than the height of the extensions 15, 16,as clearly indicated in Figs. 2 and 4, thereby leaving between the loweredge 18 and the top surface of the next subjacent stretcher, arelatively narrow opening or space 19. This lower edge 18 extendsinwardly a relatively short distance, as clearly seen in Fig. 4, and theback surface of the curtain is given a slope or inclination upwardly andrearwardly until it joins the lower surface 20 of the stretcher at apoint considerably within the rear face r of the stretcher.

By this arrangement, it will be seen by reference to Fig. 6, that theangle of repose of the filling material, indicated by the dotted line21, touches the corners 22 and 23 of the stretcher and the curtainrespectively, and strikes the top surface of the subjacent stretcher atthe point 24, well within the front face 7 of the stretcher wall. Theconstruction described has the advantage of bringing the fillingmaterial to rest upon the top surface of the stretcher at the point 24,so far within the front face that the filling will not normally spillout through the openlngs 19.

It will be noted that the angular rear surface of the curtain 17 and thebottomsurface 18 of the stretcher define a triangular air space abovethe angle of repose line, WhlCh will effectually accommodate additionalfilling material which may result from freezlng or other temporarycauses. Thus the normal lateral pressure of the filling material comesagainst the rear face 1' of the stretcher, past the corners 22 and 23,and upon that part of the top surface of the stretcher in rear of thepoint 24. Any undue or occasional lateral pressure against the angularrear face of the curtain 17 is reduced to a negligible quantity andpractically entirely avoided.

By this arrangement it is found that a very strong construction isproduced and that i there is no tendency of the curtain proper tocrumble, crack or break, while at the same time a sufficient opening 19is at all times present to take care of seepage.

I have thus far described the curtain structure of Figure 4 where thefront surface 8 of the curtain is flush with the front surface 7 of thewall of which the stretchers are a a part. In Figure 5, I haveillustrated just the reverse construction,that is to say, the longdimension surface s of the curtain 17 is flush with the rear surface 1'of the stretchers of, the same wall, and the angular surface of thecurtain extends upwardly and forwardly from its lower edge 18 to thefront face f of the stretcher.

The space 19 permits seepage of water, as

"space between the before, while the curtain 17 effectually prevents anyimproper spilling of the filling material.

In the two forms shown in Figs. 4 and 5, we have the decided advantageof the stretcher being of cross-sectional area of the minimum sizerequired for strength, and provided with an integral depending curtainso as to form in the wall, spaces 19 of minimum size; the shape of thecurtain resulting in saving a very considerable quantity of concretematerial, while providing a curtain of the desired strength.

There may be instances where it will not be necessary to apply thecurtain 17 to the header units, and on the other hand, there areinstances where it may be highly desirable to do so. One of such uses isillustrated in the end wall at the right hand side of Fig. 1.

Slight modifications ma be made in the details of construction by t oseskilled in the art, since it will be obvious that the curtain 17 may bereadily applied to formsof concrete cribbing units other than thespecific form illustrated herein.

Again, I have described the curtain 17 as depending from the lower faceof the stretcher body, but manifestly, it may extend upwardly from thetop surface thereof.

I desire to have it understood that such and other modifications anduses are embraced within the scope of the invention as set forth in theclaims appended hereto.

I claim as my invention:

1. A concrete cribbing of pre-formed, superposed headers and stretchershaving elongated substantially rectangular body portions, each headerhaving a T-shaped end adapted for self-interlocking engagement withstretcher ends, and a curtain integral with the stretcher and extendinglongitudinally between the stretcher ends, said curtain being of lessdepth than the depth of the superposed stretchers, and of a width lessthan that of the stretcher body, and tapered on its inner surface.

2. A concrete cribbing of pre-formed, superposed headers and stretchershaving elongated substantially rectangular body portions adapted toretain filling materialwithin the cribbing, each header having aT-shaped end adapted for self-interlocking engagement with stretcherends, and a curtain integral with the stretcher, extendinglongitudinally thereof between its ends, the front of the curtainand thefront of the stretcher body bein flush, and the rear surface ofthecurtain icing inclined ina plane forwardly of the natural angle ofrepose of the fill.

3. A concrete cribbing unit com rising an elongated substantiallyrectangifiar body portion having depending body spacer portions, and arelatively narrow curtain ortion of less depth than said spacer portionsextending longitudinally of said body portion between said spacerportions.

4. A concrete cri bing unit comprising an elongated substantiallyrectangular body 5 portion having depending body s acer rtions, and acurtain portion of less e th t an said spacer portions and of less wi ththan said body portion depending from said body portion flush with oneface thereof, the opposite face of said curtain bein inclined.

In testimony that I claim t 1e foregoing as my invention I aflix mysignature this 28th day of Octo ber, 1925.

JOHN M. FITZGERALD.

